Abstract:

An electrochemical immunosensor for the determination of melamine based on graphene-chitosan modified
electrode was constructed. Indirect competitive electrochemical immunoassay was performed to determine melamine in
aqueous solutions. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were carried out to monitor the
fabrication steps of immunoreaction system in solutions containing K3Fe(CN)6 as redox probe. The immunosensor demonstrated
excellent melamine detection features with a broad linear range of 5 to 1500 ng/mL and a detection limit of 0.2 ng/mL. A good
recovery of melamine in the range of 104%–106.2% was obtained in spiked milk samples.

Key words: graphene, chitosan, melamine, electrochemical immunosensor